A Late Roman Lead seal in the image of a late Roman Emperor, as attested
by crown visible with the center jewel. The image is very late Roman
in style, with the head/face on image, that begins to be common on some
later roman coins beginning under Arcadius (383-408 AD). Also the
features and style of the image are very reminiscent of later roman
mosaics and engravings.

There are letters visible around the head area, which are somewhat
difficult to make out:

Option 1: [THEO]DOSIV[S]
402-450- AD

Option 2: [C] ONSTA
[NTIVS] 420 AD

The image does share
a striking resemblance to Theodosius I (or second possibly)

The lead seal was
used to secure Imperial shipments, which may have included gifts or bribes
to other foreign powers, or for supplies to the troops. Finding one with
part of an insclription on it is quite rare and unusual. The hole on
the reverse is still visible showing where the wire or binding was put
through the lead.

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**Note on background.
Close up view of the wall of the Colosseum of Pula, Croatia.
Picture taken2014